Manipulator

ABSTRACT

According to this invention, there is provided a manipulator which prevents the distal end portion of a manipulating member from moving even if its posture is changed, and a minute object manipulating apparatus using the manipulator. The manipulator of the invention includes, for example, a manipulating target object manipulating member which is driven and controlled by a plurality of free rotation axes. All the free rotation axes cross at one point, and the manipulation distal end portion of the manipulating member is placed near the intersection.

FIELD OF THE INVENTION

[0001] The present invention relates to a manipulator such as a minutecomponent assembly apparatus which assemblies a minute object such as amicromachine component or unit by using a magnifying observation devicesuch as an optical microscope, electron microscope, or scanningtunneling microscope, or a compact manipulator apparatus which performsdiagnosis, medical treatment, research, biological production, or thelike by physically manipulating, for example, minute tissues, cells, orgenes of a living body and a minute object manipulating apparatus usingthe manipulator.

BACKGROUND OF THE INVENTION

[0002] There have been known a technique of controlling the posture of amanipulating member (end-effector) by rotating a general size arm usinga general size bearing and a technique of performing a necessary processon a minute work in a working device by rotating an arm or tool along anarcuated guide (see, for example, Japanese Patent Laid-Open No.7-256575).

[0003] In a conventional apparatus like those described above, if thedistal end of an end-effector is not located on the rotation axis of abearing or arcuated guide, the distal end of the end-effector moves outof the visual field or depth of focus of a microscope due to posturecontrol operation. This makes it necessary to position the microscopeand the distal end of the end-effector again. As described above, in amanipulator which manipulates a minute object, when the posture of theend-effector at the distal end is controlled, the manipulation targetobject often moves out of the visual field of the microscope. In aconventional manipulator having three degrees of rotational freedom, inparticular, since the rotation axes corresponding to the respectivedegrees of freedom do not coincide with each other and do not cross atone point, the distal end of the end-effector tends to move out of thevisual field or depth of focus of the microscope due to posture controloperation. In such a case, the microscope and the distal end of theend-effector must be positioned again. This operation requires a longperiod of time.

SUMMARY OF THE INVENTION

[0004] It is an object of the present invention to provide a manipulatorsuch as a compact manipulator apparatus which solves the above problemsand manipulates a minute target object, and a minute object manipulatingapparatus or the like using the manipulator.

[0005] In order to achieve the above object, according to the presentinvention, there is provided a manipulator comprising: a manipulationtarget object manipulating member being driven and controlled by aplurality of free rotation axes; all the plurality of free rotation axescrossing at one point; and, a manipulation distal end portion of themanipulating member being placed near the intersection.

[0006] According to this arrangement, the manipulator has a mechanism inwhich a plurality of (typically three) free rotation axes cross at onepoint, and the distal end portion of a manipulating member(end-effector) which manipulates a manipulation target object is placednear the intersection. With this structure, even if, for example, theposture of the end-effector is changed, its distal end portion can bemade to remain within the visual field of a microscope.

[0007] The following embodiment can be provided on the basis of theabove basic arrangement.

[0008] According to an embodiment of the present invention, themanipulating member is integrally mounted on a spherical shell movablemember, the manipulation distal end portion of the manipulating memberis placed near the center of the spherical shell movable member, thespherical shell movable member is in contact with a vibration memberwhich can vibrate, and rotation of the spherical shell movable memberaround the center thereof is controlled by controlling vibration of thevibration member, thereby controlling a posture of the manipulatingmember.

[0009] When the rotation of the movable member in the form of aspherical shell is controlled by controlling the vibration of thevibration member, the distal end portion of the end-effector is made toremain within the visual field of the microscope even if the posture ofthe end-effector is changed.

[0010] According to another embodiment of the present invention, themanipulator further comprises: first rotating means for rotating a firstrotating shaft on which a first arm is mounted; second rotating meansfor rotating a second rotating shaft which is mounted on the first armand on which a second arm is mounted; and third rotating means forrotating a third rotating shaft which is mounted on the second arm andon which a third arm is mounted, wherein the manipulating member ismounted on the third rotating shaft, and the first, second, and thirdrotating shafts pass through a manipulation distal end portion of themanipulating member.

[0011] In addition, in order to achieve the above object, according tothe present invention, there is provided a minute object manipulatingapparatus comprising: a manipulator comprising a manipulation targetobject manipulating member being driven and controlled by a plurality offree rotation axes, all the plurality of free rotation axes crossing atone point, and a manipulation distal end portion of the manipulatingmember being placed near the intersection; a magnifying observationdevice for magnifying observation of the manipulation target object andthe manipulation distal end portion of the manipulating member; and aremote controller for remotely controlling the manipulator.

[0012] This apparatus also makes the most of the advantages of the abovemanipulator. In addition, for example, the manipulator can be placed onthe upper side of a manipulation target object, and the magnifyingobservation device can be placed on the lower side of the manipulationtarget object.

[0013] Other features and advantages of the present invention will beapparent from the following description taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

[0015]FIG. 1 is a view for explaining the main part of the firstembodiment;

[0016]FIGS. 2A to 2D are views for explaining the driving principle of amultiple degree-of-freedom vibration actuator used in the firstembodiment;

[0017]FIGS. 3A to 3D are views for explaining another example of themultiple degree-of-freedom vibration actuator;

[0018]FIGS. 4A to 4D are views for explaining still another example ofthe multiple degree-of-freedom vibration actuator;

[0019]FIG. 5 is a view for explaining still another example of themultiple degree-of-freedom vibration actuator;

[0020]FIG. 6 is a view for explaining the second embodiment;

[0021]FIG. 7 is a view showing a modification of the above embodiment;and

[0022]FIG. 8 is a view for explaining the main part of the thirdembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Preferred embodiments of the present invention will now bedescribed in detail in accordance with the accompanying drawings.

First Embodiment

[0024] The first embodiment of the present invention will be describedfirst with reference to FIGS. 1 and 2A to 2D. This embodiment uses amechanism in which all the axes corresponding to three degrees ofrotational freedom cross at one point. In this system, the center of thedistal end manipulating portion of an end-effector is placed near thecenter of the spherical rotating member of a vibration actuator havingthree degrees of freedom like the one disclosed in Japanese PatentLaid-Open No. 11-220891. In such a vibration actuator, rotation axes canbe arbitrarily set. Since all the rotation axes pass through the centerof a spherical rotating member, a simple system with high rigidity canbe formed by using this actuator. As a sensor for feeding back theposition and velocity of the spherical rotating member, atwo-dimensional position sensor using a detection principle like thatdisclosed in Japanese Patent Laid-Open No. 10-65882 is suitably used.This sensor irradiates a spherical surface with light emitted from anirradiation source based on the optical mouse system or the like to forman irradiation pattern constituted by a high-luminance region and arelatively low-luminance region corresponding to the minute shape of thespherical surface. Movement information is then obtained by using themovement of the irradiation pattern based on the relative movementbetween the spherical surface and the sensor.

[0025]FIG. 1 is a view which is most indicative of the main part of thisembodiment. Reference numerals 20-1, 20-2, and 20-3 denote the first,second, and third elastic member vibration elements of a multipledegree-of-freedom vibration actuator, respectively; and 1-1 and 1-2,piezoelectric ceramics which generate bending vibrations andlongitudinal vibrations, respectively. Each vibration element 20 isfixed/supported on a frame (not shown) with an arm portion (see 1-2′ inFIG. 6) extending from an electrode plate portion for a piezoelectricceramic in the radial direction. The driving principle and arrangementof the multiple degree-of-freedom vibration actuator will be describedin detail later.

[0026] Reference numeral 2 denotes a movable member in the form of aspherical shell whose spherical surface comes into contact with thevibration element 20-1. In this embodiment, only a portion of themovable member 2 is a spherical surface, which comes into contact withthe vibration element 20-1. The mechanism of driving control will bedescribed later. Reference numeral 3 denotes a micro-hand which isintegrally mounted on the mount portion of the lower portion of themovable member 2 in the form of a spherical shell. The micro-hand 3 hasmanipulation functions such as a function of grasping or releasing aminute object such as a cell and a function of performing a process suchas forming a hole in a minute object or cutting it. The micro-hand 3 isplaced near the center of the spherical surface of the movable member 2.Reference numeral 4 denotes a vessel in which a minute object such as acell is stored. The vessel 4 is made of a transparent material such asglass. A liquid such as physiological saline solution is often containedin the vessel 4. Reference numeral 5 denotes an X-Y or X-Y-Z stage whichcan adjust the relative position between the micro-hand 3 and a minuteobject as a manipulation target object by adjusting the position of thevessel 4 on the stage; and 6, a magnifying observation device such as amicroscope, which magnifies images of the manipulation target object andmicro-hand 3 to allow observation of them. Referring to FIG. 1, themagnifying observation device 6 allows observation from below thetransparent vessel 4 through the hole in the center of the X-Y-Z stage5. Reference numeral 7 denotes a magnet which attracts and holds themovable member 2 made of iron, and also has a function of bringing thespherical surface of the movable member 2 into contact with thevibration element 20-1 with a constant pressure.

[0027] The details of the multiple degree-of-freedom vibration actuatorwill be described. FIGS. 2A to 2D show the driving principle of thisvibration actuator. A piezoelectric element 33 serving as anelectro-mechanical energy converting element which provides thedisplacements shown in FIGS. 2B to 2D is clamped/fixed betweencylindrical elastic members 31 each serving as a single vibrationmember. The piezoelectric element is formed by stacking a plurality ofsingle piezoelectric element plates with electrode plates being insertedbetween the piezoelectric element plates as needed. This allows analternating signal for driving to be applied to each necessarypiezoelectric element plate. In this case, the piezoelectric element 33repeats expansion and contraction displacements in the axial directionupon application of alternating signals, and includes the firstpiezoelectric element which excites longitudinal vibration as adisplacement in the direction of the z-axis of the three axes, i.e., thex-axis, y-axis, and z-axis, as shown in FIG. 2B, the secondpiezoelectric element which excites transverse (bending) vibrationwithin the z-x plane as shown in FIG. 2C, and the third piezoelectricelement which excites transverse (bending) vibration within the z-yplane as shown in FIG. 2D. The above first piezoelectric element isuniformly polarized in the thickness direction. Each of the second andthird piezoelectric elements is polarized such that the portions on bothsides of the diameter have opposite polarities in the thicknessdirection.

[0028] When, for example, alternating signals having a phase differenceof 90° are applied to the second and third piezoelectric elements, twobending vibrations in the vibration member combine to form an ellipticmotion around the z-axis (within the x-y plane) on the surface of thevibration member. In this case, since the natural frequency of thevibration member with respect to the x-axis is almost equal to that withrespect to the y-axis, the above elliptic vibration can be generated byapplying alternating signals having this natural frequency as a drivingfrequency to the second and third piezoelectric elements.

[0029] When an alternating signal having a frequency almost equal to thenatural frequency in the z-axis direction of the vibration member isapplied to the first piezoelectric element, the vibration member repeatslongitudinal vibration of the primary mode at a predetermined period. Inthis case, when an alternating signal is applied to the secondpiezoelectric element to excite vibration of one period matching (almostmatching) with one period of longitudinal vibration in the vibrationmember, an elliptic motion is produced within the x-z plane at a pointon the surface of the vibration member, thereby obtaining a drivingforce in the x-axis direction (around the y-axis). In this case, sincethe natural frequency of the vibration member in the z-axis directiondiffers from the natural frequency of the primary mode of bendingvibration in the x-z plane, the second piezoelectric element is drivenin the secondary mode of the natural frequency of bending vibration inthe x-axis direction, thereby matching the period of longitudinalvibration with the period of bending vibration, as shown in FIG. 2C.

[0030] Likewise, when an alternating signal is applied to the thirdpiezoelectric element to excite vibration of one period matching (almostmatching) with one period of longitudinal vibration in the vibrationmember, an elliptic motion is produced within the y-z plane at a pointon the surface of the vibration member, thereby obtaining a drivingforce in the y-axis direction (around the x-axis). In this case, sincethe natural frequency of the vibration member in the z-axis directiondiffers from the natural frequency of bending vibration within the y-zplane, the third piezoelectric element is driven in the secondary modeof the natural frequency of bending vibration in the y-axis direction,thereby matching the period of longitudinal vibration with the period ofbending vibration, as shown in FIG. 2D. That is, when an alternatingsignal having a frequency similar to the natural frequency of avibration member 1, e.g., an AC voltage, is applied to the first,second, and third piezoelectric elements, longitudinal vibration ortransverse (bending) vibration having a natural frequency is excited inthe vibration member as shown in FIGS. 2B to 2D. When an alternatingsignal is selectively applied to two of the first, second, and thirdpiezoelectric elements, the longitudinal vibration of the vibrationmember 1 is combined with transverse (bending) vibration in a directionperpendicular to that of the longitudinal vibration to produce anelliptic motion at a point on the surface of the vibration member 1. Forexample, the vibrations shown in FIGS. 2B and 2C are combined with eachother to produce an elliptic motion within the x-z plane. When thevibrations shown in FIGS. 2B and 2D are combined with each other, anelliptic motion within the y-z plane is produced. When the vibrationsshown in FIGS. 2C and 2D are combined with each other, an ellipticmotion within the x-y plane is produced.

[0031] When, therefore, a movable member (the movable member 2 inFIG. 1) is pressed against a portion of the vibration member, themovable member can be driven in a plurality of directions. In this case,elliptic motions around the three axes (within three orthogonal planes)can be produced by combining three-phase piezoelectric elements (first,second, and third piezoelectric elements). This makes it possible torealize a vibration actuator which can be driven within three orthogonalplanes by using a single vibration member.

[0032]FIG. 1 shows the basic arrangement of a vibration member in thevibration actuator of this embodiment shown in FIG. 1. In this case, thevibration member includes the first elastic member vibration element20-1 having a female threaded portion formed in the inner diameterportion and the second and third elastic member vibration elements 20-2and 20-3 each having a hole formed in a central portion. Thepiezoelectric elements 1-2 and 1-1 are placed between the first elasticmember vibration element 20-1 and the second elastic member vibrationelement 20-2 and between the second elastic member vibration element20-2 and the third elastic member vibration element 20-3. A fasteningbolt 22 which is inserted from the third elastic member vibrationelement 20-3 side and serves as a central shaft member is screwed in thefemale threaded portion of the first elastic member vibration element20-1. With this structure, the piezoelectric elements 1-2 and 1-1 areclamped between the first elastic member vibration element 20-1 and thesecond elastic member vibration element 20-2 and between the secondelastic member vibration element 20-2 and the third elastic membervibration element 20-3 so as to be integrally coupled to each other.

[0033] In this embodiment, the piezoelectric element 1-2 placed betweenthe first elastic member vibration element 20-1 and the second elasticmember vibration element 20-2 is the first piezoelectric element whichexcites, for example, longitudinal vibration in the vibration member.The piezoelectric element 1-1 placed between the second elastic membervibration element 20-2 and the third elastic member vibration element20-3 includes the second piezoelectric element which produces bendingvibration within the x-z plane and the third piezoelectric element whichproduces bending vibration within the y-z plane. The second and thirdpiezoelectric elements are so positioned as to have a phase differenceof 90°.

[0034] The inner surface of the distal end portion of the first elasticmember vibration element 20-1, which comes into contact with the movablemember 2 in the form of a spherical shell and is oblique with respect tothe axis, is formed into a tapered surface. In this embodiment,therefore, the movable member 2 in the form of a spherical shell can berotated about the x-axis, y-axis, and z-axis by combining two kinds ofvibrations of longitudinal vibration and vibrations in the twodirections which are produced in the vibration member. For example, acombination of the vibrations shown in FIGS. 2B and 2D can rotate themovable member 2 about the z-axis, a combination of the vibrations shownin FIGS. 2B and 2C can rotate the movable member 2 about the y-axis, anda combination of the vibrations shown in FIGS. 2B and 2D can rotate themovable member 2 about the x-axis. That is, the movable member 2 canrotate about three orthogonal axes. By controlling the vibrations of thevibration elements 20, the movable member 2 can be rotated/controlledabout an arbitrary axis. In this case, since the micro-hand 3 is locatedat the center of the spherical surface of the movable member 2, only theposture of the micro-hand 3 always changes at the same position. Even ifposture control operation is done, since the position of the micro-hand3 does not change, the manipulation target object never moves out of thevisual field of the microscope 6.

[0035] The above description has exemplified control on the posture ofthe micro-hand 3. When, however, the posture of a manipulation targetobject such as a cell is to controlled, it suffices if the posture ofthe micro-hand 3 is changed after the manipulation target object isgrasped by the micro-hand 3, and then the manipulation target object isreleased. In this case as well, since the position of the manipulationtarget object does not change, it never moves out of the visual field ofthe microscope 6.

[0036] In the apparatus of this embodiment, the relative position of amanipulation target object can be adjusted by the X-Y-Z stage 5, and theposture and direction of the object can be adjusted by controlling thevibrations of the vibration elements 20-1 to 20-3.

[0037] Although FIG. 1 shows the rod-like vibration elements, vibrationelements like those shown in FIGS. 3A to 3D or FIGS. 4A to 4D may beused. According to the form of the vibration actuator shown FIGS. 3A to3D, a single vibration member 200 is formed by joining a cylindricalelastic member 201 to a disk-like elastic member 202. The elastic member201 is actually divided into two portions, and piezoelectric elements203 and 204 serving as two electro-mechanical energy converting elementsare clamped between the two portions. Piezoelectric elements 205 a to205 d serving as four electro-mechanical energy converting elements arearranged on the surface of the disk-like elastic member 202.

[0038] The piezoelectric element 203 is used to displace the elasticmember 201 serving as a driving portion in the x-axis direction, asshown in FIG. 3C. The piezoelectric element 204 is used to displace theelastic member 201 in the y-axis direction. As shown in FIG. 3B, thepiezoelectric elements 203 and 204 have a polarization phase differenceof 90°. On the other hand, all the piezoelectric elements 205 a to 205 dare polarized to have the same characteristics. When the disk-likeelastic member 202 is bent as shown in FIG. 3D, the elastic member 201serving as a driving portion is displaced in the z-axis direction.

[0039] A spherical movable member 206 (the movable member 2 in FIG. 1)is in contact with the elastic member 201 serving as a driving portion.The movable member 206 can be rotated about the x-axis by supplyingalternating signals to the piezoelectric element 204 and thepiezoelectric elements 205 a to 205 d with, for example, a phasedifference of 90°. By supplying alternating signals to the piezoelectricelement 203 and the piezoelectric elements 205 a to 205 d with, forexample, a phase difference of 90°, the movable member 206 can berotated about the y-axis. When the movable member 206 is to be rotatedabout z-axis, alternating signals are supplied to the piezoelectricelements 203 and 204 with, for example, a phase difference of 90°

[0040] According to the form of the vibration actuator shown FIGS. 4A to4D, a single vibration member 300 is formed by joining a cylindricalelastic member 301 to a disk-like elastic member 302. The elastic member301 incorporates a permanent magnet (not shown) to always attract amovable member 306 (the movable member 2 in FIG. 1) made of a magneticmaterial so as to obtain pressing force. Four piezoelectric elements(polarized regions) 303 a to 303 d serving as electro-mechanical energyconverting elements are arranged on the surface of the elastic member302. By selectively supplying alternating signals to the piezoelectricelements 303 a to 303 d, the elastic member 301 serving as a drivingportion can be displayed in the x-axis direction, y-axis direction, orz-axis direction, as shown in FIGS. 4B to 4D. When the movable member306 is to be rotated about the x-axis, a displacement in the y-axisdirection (FIG. 4C) and a displacement in the z-axis direction (FIG. 4D)may be provided with, for example, a phase difference of 90°. When themovable member 306 is to be rotated about y-axis, a displacement in thex-axis direction (FIG. 4B) and a displacement in the z-axis direction(FIG. 4D) may be provided with, for example, a phase difference of 90°.When the movable member 306 is to be rotated about z-axis, adisplacement in the x-axis direction (FIG. 4B) and a displacement in they-axis direction (FIG. 4C) may be provided with, for example, a phasedifference of 90°. Alternating signals are supplied to the piezoelectricelements 303 a to 303 d in the same manner as in the form shown in FIGS.3A to 3D.

[0041] Alternatively, a plate-like vibration member like the onedisclosed in Japanese Patent Laid-Open No. 2002-272147 may be used. FIG.5 shows this vibration member. In this case, contact projections PC1 toPC4 are integrally formed at almost the middles of the four sides of aplate-like vibration member 402. A projection PG having a magnet 405 forattracting a movable member (the movable member 2 in FIG. 1) is formedat a central portion of the vibration member, and projections PE1 to PE4are formed at the four corners of the vibration member. A vibrationelement 401 is formed by bonding/fixing a piezoelectric element 403 tothe vibration member 402. The piezoelectric element 403 is driven toexcite three different natural vibration modes in the vibration element401. Combining these modes makes it possible to realize multipledegree-of-freedom driving, e.g., rotation about three orthogonal axesand rotation in two direction and about one axis.

[0042] Referring to FIG. 1, the micro-hand 3 serving as an end-effectoris placed in the center of the spherical movable member 2. However, thepresent invention is not limited to this. For example, the micro-hand 3may be replaced with a micro-tool which cuts a manipulation targetobject or forms a hole in the object.

Second Embodiment

[0043]FIG. 6 is a view for explaining the second embodiment of thepresent invention. Since reference numerals 1 to 5, 7, 20, and 22 inFIG. 1 denote the same parts as in FIG. 6, a description thereof will beomitted. Reference numerals 6-1 and 6-2 denote microscopes formagnifying observation. In this embodiment, more visual information isacquired by using two microscopes placed at upper and lower positions,thereby improving operability. The two microscopes may have the samemagnification power. However, decreasing the magnification of the lowermicroscope 6-1 to allow observation with a wide visual field will allowboth observation with a low magnification and a wide visual field andobservation with a high magnification and a narrow visual field.

[0044] Reference numerals 8-1 and 8-2 denote optical sensors, whichdetect relative position changes of a vibration elements 20 and movablemember 2. A technique like that disclosed in Japanese Patent Laid-OpenNo. 10-65882 can be used. The sensors 8-1 and 8-2 are identical sensors.The rotation axis and rotational speed of the movable member 2 can beobtained from movement information at two positions on the sphericalsurface. The sensors 8-1 and 8-2 are not limited to this system as longas they are two-dimensional position sensors. Although an example of anon-contact optical system is shown in FIG. 6, for example, a ball mousesystem may be used, in which the rotations of balls in contact with themovable member 2 are separately detected as rotation components aroundtwo axes in two directions. The sensors 8-1 and 8-2 are mounted on abase 10 with a fixed frame 9. The vibration elements 20 are mounted onthe fixed frame 9 with arm portions 1-2′ radially extending from anelectrode plate portion for a piezoelectric ceramic 1-2. Other pointsare the same as those in the first embodiment.

[0045]FIG. 7 shows a modification in which the axis of the multipledegree-of-freedom vibration actuator is tilted. For example, thestructure shown in FIG. 7 is effective for a case wherein twomicro-hands 3 are used. The multiple degree-of-freedom vibrationactuator may be located in any direction as long as the microscope 6 andstage 5 do not interfere with each other even if the spherical shell ofthe movable member 2 rotates in various directions. However, a widermovable range of the movable member 2 can be ensured by matching theoptical axis of the microscope 6 with the axis of the multipledegree-of-freedom vibration actuator as shown in FIGS. 1 and 6.

Third Embodiment

[0046]FIG. 8 is a view for explaining the third embodiment. In thissystem, the rotating axes, each having one degree of freedom, are madeto cross at one point, and the center of an end-effector is located nearthe intersection. Each axis is driven and controlled by a general rotarymotor. However, an ultrasonic motor, electrostatic motor, or the likemay be used. A system can be formed by using a general rotary encoder asa sensor which feeds back position information and velocity information.

[0047]FIG. 8 shows only a mechanism which controls the posture of amicro-hand 3. Although an X-Y-Z stage 5 and microscope 6 are arranged inthe same manner as in the above embodiments, an illustration thereof isomitted in FIG. 8. Reference numeral 11 denotes a general rotary motor,which incorporates a position sensor such as an encoder. The rotarymotor 11 is fixed to a fixed frame 9 along the z-axis which is theoptical axis of the microscope 6 (not shown). An arm 15 is mounted on arotating shaft 14. A rotary motor 12 similar to the rotary motor 11 ismounted on the distal end of the arm 15. An axis Z of the rotary motor11 is perpendicular to an axis Y of the rotary motor 12. An arm 17 isalso mounted on a rotating shaft 16 of the rotary motor 12. A similarrotary motor 13 is also mounted on the distal end of the arm 17. Theaxis Y of the rotary motor 12 is perpendicular to an axis X of therotary motor 13. The micro-hand 3 is mounted on the distal end of arotating shaft 18 of the rotary motor 13. The rotating shafts of therotary motors 11, 12, and 13 pass through the distal end portion of themicro-hand 3. In this mechanism as well, the position of the distal endportion of the micro-hand 3 does not change regardless of how the rotarymotors 11, 12, and 13 rotate, and hence the same function as that in thefirst embodiment is realized.

[0048] Although the X- and Y-axes, and the Y- and Z-axes intersect atright angles, the X- and Z-axes need not necessarily intersect at aright angle. Although the mechanism of the first embodiment is simplerand has higher rigidity, it requires relatively complicated control. Incontrast to this, the mechanism of the third embodiment is relativelycomplicated and has lower rigidity, but requires only simple control.

[0049] As has been described above, the manipulator according to apreferred embodiment of the present invention has a mechanism in whichall rotatable shafts cross at one point, and the distal end portion of amanipulating member (end-effector) which manipulates a manipulationtarget object is placed near the intersection. With this structure, evenif the posture of the manipulating member is changed, its distal enddoes not move. When, therefore, the operator is to manipulate amanipulation target object while observing it with a microscope or thelike, the object can be made to always remain in the visual field. Thiseliminates the necessity of position the microscope and end-effectoragain every time the position of the end-effector or manipulation targetobject (e.g., a minute object) is controlled. Therefore, very efficientoperation can be performed.

[0050] As many apparently widely different embodiments of the presentinvention can be made without departing from the spirit and scopethereof, it is to be understood that the invention is not limited to thespecific embodiments thereof except as defined in the claims.

What is claimed is:
 1. A manipulator comprising: a manipulation targetobject manipulating member being driven and controlled by a plurality offree rotation axes; all the plurality of free rotation axes crossing atone point; and a manipulation distal end portion of said manipulatingmember being placed near the intersection.
 2. The manipulator accordingto claim 1, wherein said manipulating member is integrally mounted on aspherical shell movable member, the manipulation distal end portion ofsaid manipulating member is placed near the center of the sphericalshell movable member, the spherical shell movable member is in contactwith a vibration member which can vibrate, and rotation of the sphericalshell movable member around the center thereof is controlled bycontrolling vibration of the vibration member, thereby controlling aposture of said manipulating member.
 3. The manipulator according toclaim 1, further comprising: first rotating means for rotating a firstrotating shaft on which a first arm is mounted; second rotating meansfor rotating a second rotating shaft which is mounted on the first armand on which a second arm is mounted; and third rotating means forrotating a third rotating shaft which is mounted on the second arm andon which a third arm is mounted, wherein said manipulating member ismounted on the third rotating shaft, and said first, second, and thirdrotating shafts pass through a manipulation distal end portion of saidmanipulating member.
 4. A minute object manipulating apparatuscomprising: a manipulator comprising a manipulation target objectmanipulating member being driven and controlled by a plurality of freerotation axes, all the plurality of free rotation axes crossing at onepoint, and a manipulation distal end portion of said manipulating memberbeing placed near the intersection; a magnifying observation device formagnifying observation of the manipulation target object and themanipulation distal end portion of said manipulating member; and aremote controller for remotely controlling said manipulator.
 5. Theapparatus according to claim 4, wherein said manipulator is placed on anupper side of the manipulation target object, and said magnifyingobservation device is placed on a lower side of the manipulation targetobject.